This section provides background information related to the present disclosure which is not necessarily prior art.
The hard and soft tissues of the mouth are covered with microbial populations that include bacteria having different metabolic capabilities where the microbial populations may include both Gram-positive bacteria and Gram-negative bacteria. Generally, Gram-positive aerobic bacteria readily catabolize carbohydrates to produce acids which attack the hard tissues of the oral cavity, and which over time may result in the formation of dental carious lesions (cavities). In contrast, Gram-negative anaerobic bacteria readily metabolize various amino acids included in salivary peptides and proteins to form end-products which favor a formation of oral malodor and gingivitis-periodontitis. This process of peptide, protein and amino acid degradation by the mouth bacteria is referred to as oral bacterial putrefaction. The mixture of malodorous compounds produced by the Gram-negative anaerobic bacteria during putrefactive degradation of proteins, peptides and amino acids include hydrogen sulfide, methyl mercaptan, and dimethyl sulfide (formed from the sulfur-containing amino acids cysteine, cystine and methionine); indole and skatole (formed during the metabolism of tryptophan); cadaverine and putrescine (produced from lysine and ornithine); and butyrate and valerate (produced from the metabolism of other amino acids). The production of these malodorous compounds in the oral cavity results in a condition commonly referred to as oral malodor.
Hydrogen sulfide, methyl mercaptan, butyrate and propionate are putrefaction end-products that also have cell and tissue altering non-inflammatory roles in the periodontitis process. Hydrogen sulfide and methyl mercaptan are compounds particularly effective in facilitating the toxins and other-penetrability of oral epithelium by large molecular weight compounds produced by Gram-negative anaerobic bacteria, and leading to the inflammation and tissue degradation characteristics of gingivitis and periodontitis. Gingivitis is a condition in which the gingiva is red, swollen and bleeding. If left untreated, gingivitis may develop into periodontitis, a condition characterized by destruction of the periodontium, including epithelial attachment loss, periodontal membrane and ligament destruction, and loss of gingiva and alveolar bone. Severe periodontitis resulting in deep periodontal pockets may ultimately result in tooth loss.
Previous studies have largely focused on the use of germicidal agents to treat gingivitis-periodontitis and oral malodor. These studies have not recognized that gingivitis-periodontitis and oral malodor arise from a common process, namely oral bacterial putrefaction; and also that this putrefaction can be inhibited by simultaneously lowering the ability of the oral bacteria to reduce the oxidation-reduction potential (Eh) of the oral cavity and at the same time, raising the existing Eh to where the oral environmental Eh is not conducive to oral putrefaction and oral disease production.
U.S. Pat. No. 6,929,790 to Kleinberg et al., which is a continuation application of U.S. Pat. No. 6,423,300 which is a divisional application of U.S. Pat. No. 6,409,992, reports an oral composition comprising a zinc compound and at least one Eh raising compound.
U.S. Pat. No. 6,723,305 to DePierro et al. reports an oral composition comprising a zinc compound and CPC.